Brookneal Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Brookneal. A median date has an even chance of a later freeze in spring, or an earlier one in fall.
The last spring freeze typically comes around April 17 and the first fall freeze around October 24, a growing season of about 188 days.
- Median at 36°F
- last April 29, first October 15
- Median at 32°F
- last April 17, first October 24
- Median at 28°F
- last April 4, first November 1
Last freeze in spring
The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 15 | May 10 | May 5 | May 2 | Apr 29 | Apr 26 | Apr 22 | Apr 18 | Apr 14 |
| 32°F | May 5 | Apr 29 | Apr 24 | Apr 20 | Apr 17 | Apr 14 | Apr 11 | Apr 7 | Apr 2 |
| 28°F | Apr 19 | Apr 13 | Apr 10 | Apr 7 | Apr 4 | Apr 1 | Mar 30 | Mar 26 | Mar 20 |
| 24°F | Apr 6 | Apr 1 | Mar 30 | Mar 26 | Mar 22 | Mar 19 | Mar 16 | Mar 12 | Mar 5 |
| 20°F | Mar 27 | Mar 20 | Mar 16 | Mar 13 | Mar 9 | Mar 5 | Feb 28 | Feb 24 | Feb 14 |
| 16°F | Mar 17 | Mar 10 | Mar 4 | Feb 28 | Feb 24 | Feb 16 | Feb 10 | Feb 4 | Jan 26 |
First freeze in fall
The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 3 | Oct 7 | Oct 10 | Oct 13 | Oct 15 | Oct 18 | Oct 21 | Oct 24 | Oct 28 |
| 32°F | Oct 10 | Oct 14 | Oct 18 | Oct 22 | Oct 24 | Oct 27 | Oct 29 | Nov 1 | Nov 5 |
| 28°F | Oct 17 | Oct 23 | Oct 28 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 15 |
| 24°F | Oct 28 | Nov 1 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 18 | Nov 24 | Dec 1 |
| 20°F | Nov 7 | Nov 13 | Nov 18 | Nov 23 | Nov 27 | Dec 1 | Dec 4 | Dec 9 | Dec 20 |
| 16°F | Nov 22 | Nov 30 | Dec 3 | Dec 8 | Dec 15 | Dec 22 | Dec 30 | Jan 5 | Jan 14 |
Growing season length
Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | 187 | 181 | 177 | 172 | 169 | 165 | 160 | 155 | 148 |
| 32°F | 208 | 201 | 197 | 193 | 188 | 185 | 180 | 175 | 168 |
| 28°F | 231 | 224 | 219 | 214 | 211 | 207 | 203 | 198 | 190 |
| 24°F | 259 | 250 | 244 | 239 | 234 | 229 | 225 | 219 | 213 |
| 20°F | 293 | 282 | 274 | 268 | 261 | 256 | 251 | 245 | 236 |
| 16°F | 329 | 318 | 309 | 303 | 297 | 290 | 282 | 276 | 265 |
How often it gets that cold
The share of years with at least one night at or below each temperature.
- 36°F or colder
- 100% of years
- 32°F or colder
- 100% of years
- 28°F or colder
- 100% of years
- 24°F or colder
- 100% of years
- 20°F or colder
- 100% of years
- 16°F or colder
- 99% of years
Degree days
A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.
- Heating degree days, base 65°F
- 4,329
- Cooling degree days, base 65°F
- 1,245
- Growing degree days, base 40°F
- 6,572
- Growing degree days, base 45°F
- 5,186
- Growing degree days, base 50°F
- 3,971
- Growing degree days, base 55°F
- 2,915
- Growing degree days, base 60°F
- 2,007
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 902 | 0 | 12 |
| February | 731 | 0 | 16 |
| March | 595 | 3 | 71 |
| April | 286 | 22 | 227 |
| May | 101 | 98 | 465 |
| June | 12 | 249 | 687 |
| July | 1 | 362 | 826 |
| August | 2 | 328 | 790 |
| September | 48 | 157 | 560 |
| October | 279 | 26 | 243 |
| November | 569 | 1 | 56 |
| December | 805 | 0 | 17 |
What this means
NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.
The station is 2.1 km from Brookneal. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.
More
Sources
NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00441082 (Brookneal). Public domain.